Method of and apparatus for softening water.



i T. R. nueemu, METHOD OF AND APPARATUS FOR SOFTENING WATER. I APPLICATION FILED OCT. 23. IEHG- I 1,276,629. Patented Aug. 20, 191&

2 SHEETSSHEET 1.

T. R. DUGGANM.

METHOD OF AND APPARATUS FOR SOFTENING WATER.

' APPLICATION HLED OCT. 23. IEIIG.

' 1,276,629. Patented Au .20, ma

2 SHEETSSH-EET 2.

UNITED STATES PATENT OFFICE.

THOMAS DU GGA N, 01" NEW YORK, N. Y., ABBIGNOB TO THE PEBMUTIT COMPANY, OF

NEW YORK, N. Y.,--A CORPORATION OF DELAWARE.

amnion or am: arrana'rvs not. consume warm.

Specification 01. Letter! Patent.

Patented Aug. 20. 1918 Application flied October 28, 1818. Serial No. 127,127.

To all whom it may concern.-

'Be it known that L'THOMAI; R. DUGGAN, a citizen of Great Br1tain,-residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Methods of and Apparatus for Softenin Water, of which'the following is a speci cation.

This invention relates to methods of and apparatus for softenin water; and it comprises a method of .uti izing the activity of exchange silicates to a greater extent than is now the case and of quickly revivifying the same with good utilization of revivifying solutions; and it also comprises certain apparatus with connections adapted for the performance of this method; all as more fully hereinafter set forth and as claimed.

In the method of softening water by the use of exchange silicates which is now well known water-to 'be softened'kis passed throu certain materials containing silica and a unii'na (or another amphoteric o'xid', such as titanium oxid, iron oxid, chromium oxid, tin oxid, zinc oxid, etc), alkali and Water. These materials are used. in the form of small hard granules which are employed as a granular bed. 7

On the passage of hard waterthroughthe bed of granulesthe lime and magnesia compounds, td which the water owes its hardness, are taken up by the exchange silicate,

"alkali, compounds going into solution in their lieu. After a period of use when the exchangesilicate has. taken up a certain 'amount of lime andmagnes1a, it is I'BVIVI- field by passin a solution of sodium chlorid '(corninon salt through the bed. The lime and magnesia how go into solution as calcium. and magnesium 'chlorids and the exchange silicate takesup alkali again so that f it is ready f r. fleaction-w ich is possible depends u on t operative amountmf' surface offers; to the In large measure, the amount of exchange 6 water flowing through a bed or mass of ranulea The water tends morefor lessjto ollow channelstand in so doing, of course,

certain surfaces are more e' d to water than othersand thb time- 0 goperativeness,

that is," the timebefore regeneration is nee essary',

depends upon the time of operation of'theimore ekposed faces. The channeling difiicul'ties are more accentuated where the 'ever, I find certain advantages are tial passage at one point rather than at another.

Ordinarily, the water to be softened is passed throu h the bed in a downward direction and the salt solution in revivifying is also passed down-ward. In so d0ing,ythe flow of the liquid and gravitation cooperate to keep the granules in place; and the result is that, to a greater or less extent, the--de scribed preferential passage of water or liquid at some points rather than at others is favored. In the case of any given group of granules, the flow is apt to be reater past some granules and some granu e surfaces, than past Others.

- An upward passage of water in the softening phase of the apparatus avoids in large measure these difficulties, giving algreater period of activity since the buoying action of the current keeps the granules apart and prevents packing and channeling, butthis sometimes brings new difficulties; and particularly where the water is cold and the i filter warm or where the exchange silicate is light and bulky. On warming up, the water is apt to liberate air bubbles which cling to the granules and tend to liftvthem. ,The tendency to lift is of course less with the denser varieties of silicates, but these do not ive as much active surface as the lighter.

ith light granules, bad. design of apparatus, and water which warmsup materially in going through the apparatus there may, 4

be a relatively serious loss of silicates due to flotation and exit of granuleswith the softened water. Whatever be the direction of flow of water in the softening phase, how.- ained by an upward flow of salt solution in the regenerating phase. With the relatively heavy salt solution passing in an upward direction the relative movement of the granules with regard; to each other is more pronounced than it' is with a similar flow of water; and uniform passage of the saltso. lution takespl'ace.

In revivification, it is found that the main part of the absorbed bases will be remoyed by the salt solution after the regeneraztreig liquid has been supplied to and pa through the layer inan amount equal to or larger than that amount of liquid which can be stored in the spaces between the granules. Or, in other words, the liquid occurring between the granules must be displaced once or twice by the salt solution in order to remove the main part of the bases absorbed by the exchan e silicate. Repassage of the used salt so ution through the bed does little good and may do harm, since such a solution will only take up a certain amount of calcium or magnesium before losing regenerating power. .When in softening thewater flows downward and the salt solution passes upward, the lower layers of silicates are completely revived first and it is inexpedient to bring back contaminated brine into contact therewith again. It is desirable in regeneration to bring the clean or uncontaminated salt solution first into contact with the most acti e or least contaminated layers of silicates.

After the revivifying solution has been used on the exchange silicate, such solution must, as already stated, be removed to prevent the contamination of the water next to be treated. Inone way, giving a good utilization of the salt solution, I' can gradually admit fresh water at the bottom of the mass, drawing off from a point above; the admission of water being finally stopped and the residual liquid in the bed then removed by draining from the bottom. It is advanta-- geous to'choose the amount of waterin which the regenerati n salt is dissolved, so that the main part 0% the absorbed bases is taken into solution and taken away before fresh water is introduced. Other ways of remov' ing the salt solution than that indicated may be used; but the described way is economical and practical, since the whole amount of regenerating liquid is well utilized; but any other suitable way may be used. Care should however be taken that repa'ssage of contaminated salt solution through the revived or partially revived bed is avoided.

In the accompanying illustration I have shown, more or less diagrammatically, certain embodiments 'of apparatus within the presentinvention and susceptible of use in the described process. In this showing,

Figure 1 is a view, partly in elevation and partly in vertical SBCtlOIl, of a type of apparatus' in which both the-water to be softened and the .revivifying solution.

in an upwar 'dithrough the silicate be rection; and I Fig. 2 is a similar view'ofa modified structure wherein the flow of Water toibe. softened is normally downward .while that of the regenerating solution is, as before,

used in lieu, of tank A to be softened. This pipe 10'extends downcross pipe beyon the sewer connection. Th pipe (12-) beyond the'pomt of connection 'nection.

In Fig. 1 casing B contains a layer or bed 1 of exchan e silicates. As shown, this layer is kept in position by an upper perforated cross-plate 2 and a lower perforated crossplate 3, although the use of these plates is not necessary. Below the lower cross-plate is a layer 4 of gravel or the like. The granular silicates may rest directly on this gravel layer instead of being separated therefrom by the plate. And the gravel layer may be dispensed with. Below this layer is another cross-plate 5, which may be replaced by a strainer system or any other suitable structure. Below this cross-plate is open chamber 6 with .pipe connection 7 at its lowest point. Baffle 8 is arranged above this ipe connection in order to give an even distribution of they liquid. Above the upper cross-plate is an empty chamber 9. Leading from tank A "is water pipe 10 provided with'valve 10. Valved inlet ll-may be as a source of .water wardly to a cross-connection 12 communicating with the casing B at the lowest point. Leading from this cross-connection is another valved pipe 13 leading to tank D for salt solution. In lieu of tank D, salt solution maybe brought from another source through valved inlet 14.. As shown, .tank D 'is provided with a salt box 15 having perforated bottom 16'. Also leading from the water supply pipe is another cross pipe 16 provided-with valved outlet pipe 17 leading to the tank D for salt solution. As shown, this pipe is alsoprovided with a float valve 18. Beyond this valved outlet pipe (17) in the upper cross pipe is valve 19 and beyond this again is a down pipe 20 leading into the to of easing B. The upper this down pipe is prolonged tofenter soft water pipe 21. As shown, this soft water pipe has valves 22 and 23, located respectively on each side of the point of inlet of'the-upper crosspipe. Be yond thelower valve 23 the pipe is pro- 'Enged downwardly to the sewerconnection On "the top of the casing B is a valved outlet connection 24 and just above the'upper' cross-plate'is valved waste outlet 25 ending above open pipe 26'which also leads to e lowermost cross with the bottonr ofthe casing B is valved at 27 and has a connection '28 leading to the sewer connection E.

In the structure shown in Fig. 2 the upper cross-pipe is provided with a valve 29 beyond which it extends to special connection I, 30 and 31 leading down to the sewer conconnection nection E. e wer cross pipe (12) bas the same conn tion entering the bottom of the casing-B ,bt atthis point it hasanother a it illeading past valve 33 to the sewer connedtion E. Another valved connection 3* leads through pipe 35 to tank G for softened water.

In the use of the structure of- Fig. 1, the

" exchange silicate 1, being-supposed to be revived and in condition to soften hard Water, such hardwater is led in from pipe 11 or tank and passes through 10'and 12 to 7 whence it passes upward through the layer "of gravel or sand and the layer of exchange silicates to and thence through-21, valve 22 being open, to tank C, whence it goes to a place of use. After a time the activity of the exchange silicate 1 will be lessened and it will be necessary to revive. At this time 'valve 10 is closed and the'valve in 17 is opened, box 15 being su plied with the requlsite amount of salt. n amount of water controlled by floatvalve 18 enters D and dissolves the salt in the salt box. Brine from another source may of course be. supplied through pipe 14:. The salt solution passes downward through 13 and enters the bottom of thewcasing Hat 7 thence flowing upi ward to exit at 25, displacing the water before. it.as it goes andrevivifying the exchange silicate. When the amount of salt solution. desirable has been passed through, valve 13 in pipe 13 is closed and'lO' opened.

.Water flows through 10, 12 and- 7 entering the casing at its lowest point and flowing upward to 25, displacing and removing the salt solution as it goes. This passage of water in this direction may becontinued until all the salt solution has been displaced. Or valve 24 .may be opened to allow air to enter, valve 1O closed and valve .27

.opened allowing the liquid in the bed -to flow downward. through the mass and go .to exit at 7 and 28. It will be noted 5 that 7 communicates with B- at the lowest portion of the casing so as to insure a positive draining with removal of all water containin salt. If desired, the valve 24 beingclose ,19 may be opened and asupply of fresh water sentthrough the mass downwardly for washing purposes. The ex- "change silicate being now revived and washed is ready for another water softening phase as before. In the water softening operation the lower body of sand or gravel 4 andlthe perforated plates 3- and 5 catch most of the mechanical impurities and the final downward washing to get rid of the 28 to the sewer. a

1n the operation of the structure of Fig.

salt solution also servesfor back washing. Mechanical impurities go'out through 7 and .2; "'the.flow of the water to be softened is normally }d ownward, while that of the regen- ,eratingfsolution is, as before, upward. In

the operation of this structure, presuming the exchangesilicate to be regenerated and ready for operation, water from 11 or A passesfthrou h 16 and 20, valve 19 being open, into a; amber 9, and thence'through the silicate bed 1 downward to-7. From 7 the softened water passes through 34 and 35 to C. When the exchange silicate needs regeneration, the flow of water through the apparatus-is stopped and salt solutibn" pared in D (or'supplied from 1 4). This salt solution passesldownw 13, (valves 10*and 19 bei Missed the bottom of the casings through 7. Th salt solution passes upward through silicates 1 to 25 and thence through 26 to waste as before. j I 1 .In flushingwith either form of apparatus shown, wash water may of course be sent through the salt line shown coming through line 16 and pipe17 past valve 18 into D and thence downwardly through 13, past valve 13) into the bottom of the casing B through pipe 7. In so doing, a simplemanner of operation is afforded since the necessary quantity of salt may be put into box 15 and then the water-al'lowed to flow. The water at first forms the strongsalt solution necessary for reviving and then passes this salt solution upwardly through the \silicates to wasteat 25 and then washes the whole apparatus.

In the operation of the'structure of Fig. 1, the salt solution and the water pass through the mass in the same direction; While in the operation of the structure of Fig. 2, the flow of the water to be purified and that of the regenerating salt solution,

are in opposed directions. With an upward passage of bothliquids as shownin Fig. 1, the advantages of a buoying action during softening as well as during regeneration, are secured while in the case of Fig. 2, the advantage describeddue to the entry of the two liquids at opposite faces of the mass of this salt solution, which is of course substantially free of lime and magnesia, passes first through the little contaminated por-, tion of the bed and then into fcontact with contaminated solution at or near the surface I of the bed after a single Y to remove lime or ma the contaminated portion, theie taking up the lime and magnesia. tinues, the dissolved lime and magnesia are carried away from the! bed and do not reenter it.

What Iclaim is l. The process of regenerating after use a bed of water sdftening exchange silicates containing lime or magnesia, which comprises passing a salt solution through said bed in an upward direction as-long as said salt solution continues to dissolve and removesubstantial amounts of lime or magnesia, and drawing 01f the contaminated so-'- tutgon after a single passage through the 2. The processlof regenerating after use a bed of water softening exchange silicates containing lime or magnesia, which comprises passing a salt solution through said bed in an upward direction as long as said salt solution continues to dissolve and re, move substantial amounts of llme or magnesia, and drawing off the contaminated solution at or near the surface of the bed after a single passage throughthe bed.

. 3. The process of regenerating after use a bed of water softening exchan e silicates,

containing lime or magnesia, w ich comprises passing asalt solution through said bed in an upward direction, drawing of! the contaminated solution after a single p'as sage through the bed, such drawing oflbeing continued until the solution has sub stantially ceased to remove lime or magnesia, and then flushing out the residue of the solution.

I 4. The process of regenerating after use a bed of water softening exchan e silicates containing lime or ma esia, w ich comrises passing a salt softion through the ed in an upward direction, drawing of! the age through the bed, such drawing of ein continued until the solutiom has substantially ceased ing out the residue 0 the solution.

*5. The process of regenerating after use a bed of water softening exchange silicates, thrggh which the water to be softened has pas downwardly, which comprises pass ing a salt solution through'the bed in an upward direction and drawing ofi the con' taminated solution after, a through the bed. Y, v

6. he process of regenerating after use a single passage bed of water softening exchange silicates Ashram, h whichthewater to be softened has ass 'ddwnwardlyrwhich comprises passng' a salt solution through the bdin an As the flow con-' esia, and then flush therein, means or upward direction, draw' oil 'the contamiv nated-solution after a sing e passage through the bed such drawing ofl:' being continued until the solution has substantially ceased to remove lime or magnesia, and then flush ing out the residue of the solution.

7. The process of regenerating after use a bed of water softening exchange silicates through which the water to be softened has passed downwardly, which comprises passing a salt solution through the bed in an 7 upward direction, drawing ofi the contaminated solution at or near the, surface of the bed after a single passage throughmhe bed,

such drawingofl beingcontinued until the solution has substantiallyceased to remove lime or magnesia, and then flushing out-the.

residue of the solution. a

8. The process of regenerating after use a bed of water softening exchange silicates, which comprises passing salt solution through the bed in a direction opposite to bed during softening, whereby theactive salt solution cgntacts'first with the least contaminated portion of the bed, and drawing oil the contaminated solution after a singlepassage through the bed, so that contami- "nated salt solution does not contact with "relatively uncontaminated portions of said bed.

9. The process of regenerating after use a' bed of-water softening exohan e silicates,

which comprises passing", sa t solution through the bed in a direction oppositeto that in which the water flowedduring use,

that in which the water flowed through the drawing ofi the contaminated solution after wash water through such bed in an upward direction with removal of salt solution and wash waterat or above-the upperfaceof such 'bed until the silicates are regenerated, interrupting the flow at this time and draining the bed from the lowest point, and once more passing water to be softened through the bed in a downward direction.

11. In a water softening a paratus a casing, a bed of toned throughsuch d and means connected to such casing for passi salt solution therethrough upwardly wit means above such bed for removing the salt solution, and means for passing water following after and displacing such salt solution to the point of anular exc ange silicates H ing water to be sofremoval of the salt solution, such means bein connected so as to remove substantially al the solution from the casing.

12. In a water softening apparatus, a casing, a bed of exchange sll-icates therein, means for transmitting water to be softened through such'bed and means for passing salt solution through the bed upwardly to 'a pointof outlet above such bed, means for Washing out the salt solution andmeans c0n- -10 nected to the lowest point of the casing lead- ,ing to a place of disposition for removing the water used in such washing out. I In testimony whereof I affix my signature.

THQ. R.- DUGGAN. 

